This project concerns the isolation and structure determination of flavonoids, sesquiterpene lactones, diterpenes, betalains and other natural products in higher plants in order (1) to establish the distribution of these compounds and to use them as genetic markers for understanding evolution, speciation and gene-flow among populations; (2) to understand the ecological roles of such compounds, especially in terms of plant - animal co-evolution; and (3) to determine the physiological properties of the substances, including enzyme inhibitory action and antibiotic, contact dermatitis and antitumor activity. The research also concerns correlating micro- and macromolecular chemical patterns with EM and SEM-determined features of higher plants, especially betalains and sieve-element plastids in the Centrospermae, and sesquiterpene lactones and trichomes in the Compositae.